Non-thermal atmospheric pressure plasma is a novel approach for wound healing, blood coagulation, and cancer therapy. A recent discovery in the field of plasma medicine is that non-thermal atmospheric pressure plasma not only directly but also indirectly affects cells via plasma-treated liquids. This discovery has led to the use of non-thermal atmospheric pressure plasma as a novel chemotherapy. We refer to these plasma-treated liquids as plasma-activated liquids. We chose Ringer’s solutions to produce plasma-activated liquids for clinical applications. In vitro and in vivo experiments demonstrated that plasma-activated Ringer’s lactate solution has anti-tumor effects, but of the four components in Ringer’s lactate solution, only lactate exhibited anti-tumor effects through activation by non-thermal plasma. Nuclear magnetic resonance analyses indicate that plasma irradiation generates acetyl and pyruvic acid-like groups in Ringer’s lactate solution. Overall, these results suggest that plasma-activated Ringer’s lactate solution is promising for chemotherapy.

Ovarian clear cell carcinoma (CCC) is a histological type of epithelial ovarian cancer that is less responsive to chemotherapy and associated with a poorer prognosis than serous and endometrioid carcinoma. Non-thermal atmospheric pressure plasma which produces reactive species has recently led to an explosion of research in plasma medicine. Plasma treatment can be applied to cancer treatment to induce apoptosis and tumor growth arrest. Furthermore, recent studies have shown that a medium exposed to plasma also has an anti-proliferative effect against cancer in the absence of direct exposure to plasma. In this study, we confirmed whether this indirect plasma has an anti-tumor effect against CCC, and investigated whether this efficacy is selective for cancer cells. Non-thermal atmospheric pressure plasma induced apoptosis in CCC cells, while human peritoneal mesothelial cells remained viable. Non-thermal atmospheric pressure plasma exhibits selective cytotoxicity against CCC cells which are resistant to chemotherapy.

The vacuole in plant cells plays various roles that are important in the maintenance of cell organization and func- tion, yet the vacuolar function varies greatly depending on the type of cell and on the stage of plant development. The regulation of deposition of various proteins with specific functions in the vacuole is a prerequisite for the expression and maintenance of vacuolar functions. Transport of proteins from the site of synthesis to the site of deposition is generally mediated by topogenic information in the passenger protein and the cellular apparatus that recognizes it. Recent identifi- cation of some of the determinants that affect transport and sorting of proteins to the vacuole opened a new pathway to reveal how protein targeting to the vacuole can be regulated. TRAFFICKING AND SORTING OF VACUOLAR PROTEINS The vacuole is one of the organelles that constitute the complex secretory system of the cell, similar to the lysosome of animal cells and the vacuole of yeast. A11 the membranes in the secretory system are connected by traffic of various small transport vesicles, and the lumen of these membrane compartments is topologically identical to the extracellular milieu. Most, if not all, of the proteins in this compartment first enter the lumen of the ER by direction of the signal peptide in the precursor, and then they are transported to appropriate destinations without any further translocation through a membrane. Secretory proteins pass through various compartments of the Golgi apparatus, the TGN, and the secretory vesicles before they are secreted from the cell. Vacuolar proteins follow the same pathway until they are separated from secretory proteins, probably in the TGN, for specific transport to the vacuole. Basically, secretion is a bulk- flow default pathway in plants, and proteins without any topogenic information other than the signal peptide are se- creted (Chrispeels, 199 1). Vacuolar proteins should be sorted from secretory proteins at the branch point of the transport pathway by a sorting machinery that recognizes a sorting signal in the vacuolar protein.

Cancer cell–derived extracellular vesicles (EVs) have unique protein profiles, making them promising targets as disease biomarkers. High-grade serous ovarian carcinoma (HGSOC) is the deadly subtype of epithelial ovarian cancer, and we aimed to identify HGSOC-specific membrane proteins. Small EVs (sEVs) and medium/large EVs (m/lEVs) from cell lines or patient serum and ascites were analyzed by LC-MS/MS, revealing that both EV subtypes had unique proteomic characteristics. Multivalidation steps identified FRα, Claudin-3, and TACSTD2 as HGSOC-specific sEV proteins, but m/lEV-associated candidates were not identified. In addition, for using a simple-to-use microfluidic device for EV isolation, polyketone-coated nanowires (pNWs) were developed, which efficiently purify sEVs from biofluids. Multiplexed array assays of sEVs isolated by pNW showed specific detectability in cancer patients and predicted clinical status. In summary, the HGSOC-specific marker detection by pNW are a promising platform as clinical biomarkers, and these insights provide detailed proteomic aspects of diverse EVs in HGSOC patients.

Epithelial ovarian cancer (EOC) is the most lethal gynecologic malignancy. The major cause of EOC’s lethality is that intraperitoneal recurrence occurs with high frequency due to occult metastasis. We had demonstrated that plasma-activated medium (PAM) exerts a metastasis-inhibitory effect on ovarian cancer in vitro and in vivo. Here we investigated how PAM inhibits intraperitoneal metastasis. We studied PAM’s inhibition of micro-dissemination onto the omentum by performing in vivo imaging in combination with a sequential histological analysis. The results revealed that PAM induced macrophage infiltration into the disseminated lesion. The iNOS-positive signal was co-localized at the macrophages in the existing lesion, indicating that PAM might induce M1-type macrophages. This may be another mechanism of the antitumor effect through a PAM-evoked immune response. Intraperitoneal lavage with plasma-activated lactate Ringer’s solution (PAL) significantly improved the overall survival rate in an ovarian cancer mouse model. Our results demonstrated the efficiency and practicality of aqueous plasma for clinical applications.